Field of Invention
The present invention relates to a packaging structure and a power device thereof. More particularly, the present invention relates to a semiconductor packaging structure and a semiconductor power device thereof.
Description of Related Art
Power supplies are a core member of energy conversion and also an indispensable device in the current electric power industry, electronics industry, electric machinery industry and energy industry. Important characteristics of supplies are energy conversion efficiency, power intensity, heat dissipation, and so on. The qualities of the foregoing characteristics will affect the performance of a system which employs the power supply. Hence, said important characteristics are the main purpose, which the industry searches for.
Progression of the modem power supply not only depends on the advancement of active semiconductor components and passive components (i.e., capacitors and inductors), but also depends on the method combining these elements. The combination can utilize the characteristics of each element and has become one of the most important features of the power supply. For enhancing the performance of the power supply, how to dispose and combine different elements for maximizing the performance of the whole device has become the foremost topic of development. The combination must not only use separated elements to realize the interconnection but also integrate different elements through packaging or define integrating elements in chip level.
In a power supply, the elements need to speed up to decrease switching loss, but the elements should be worked in a safe way during conversion. For achieving such goal, a half-bridge circuit is a common option, and the half-bridge circuit is a basic unit for developing a variety of circuit topology so as to provide application possibility for modem power electronic device. The performance of the whole system depends on the performance of the half-bridge circuit characteristics.
During switching, switch elements change fast from high impedance to low impedance or from low impedance to high impedance. Output current flows through the upper tube and the lower tube of the bridge arm corresponding to the change of the switch elements, and elements that are switched during the above-mentioned process need to endure switching loss. Meanwhile, there are non-ideality parasitic parameters in the whole circuit, and the switching motion will lead to additional peak voltage in elements which endure Vbus such that the safety of the elements will be affected.
For decreasing loss, the most important thing is to speed up the switching speed and minimize the turning on and off duration. However, since there is parasitic inductance in circuit, speeding up the switching speed will lead to high voltage and current rate of change such that peak voltage will generate at two terminals of the element and the safety of the elements will be threatened. In addition, in special applications (i.e., low voltage and high current), except for parasitic inductance, parasitic impedance among wires will also bring loss and affect the efficiency of the whole system.
In view of the foregoing, problems and disadvantages are associated with existing products that require further improvement. However, those skilled in the art have yet to find a solution.